The Kartboy Hangman Exhaust Hangers are a direct replacement for the stock pieces on all Subaru vehicles built in the recent past. The benefits of this modification are reduced swaying of both stock and aftermarket exhaust systems, and a longer life vs. natural rubber. These pieces were computer designed and analyzed to allow minimum movement, while retaining the stock packaging requirements.
This product may fit other brands of vehicles, but it is not intended to, so purchase with caution in this situation. Extra long hangers are for exhaust systems that either ride too high, or for people who actually put a trailer hitch on their Subaru. 12/15mm refers to the size of the mounting holes, 12mm hanger is for the 08+ Impreza.